Case Presentation:
A 53 year old Russian man with no significant past medical history initially presented to an ophthalmology clinic with two days of progressively worsening, near-total left visual field loss associated with a one-week duration of fever, chills, and cough. He was diagnosed with bacterial endophthalmitis. His vitreous fluid was sampled, and he was referred to our institution for further evaluation. On presentation, patient appeared visibly toxic with diffuse rigors. Vital signs were Tmax 104.6°F, BP 135/88, HR 127, SaO2 91% on room air. Patient reported that he was born in Russia and immigrated to the United States 11 years ago; his recent travel history was limited to within the United States. Lab work performed on admission showed WBC 12.7 K/UL, AST 58 U/L, ALT 92 U/L, Alkaline Phosphatase 246 U/L, Albumin 2.1g/dL. Glucose was normal. HIV was nonreactive. CXR showed right middle and right lower lobe pneumonia. Urine culture was negative. His vitreous fluid and peripheral blood cultures grew Klebsiella pneumoniae. Pyogenic liver abscess was a concern given evidence of metastatic septic foci. An abdominal CT revealed a 6×7.5 cm multi-septated hypodense right hepatic lobe collection. Ceftriaxone was initiated and the patient underwent percutaneous hepatic drainage, which also recovered K. pneumoniae. He was ultimately discharged home to complete a 4-week total course of antibiotics. Repeat abdominal CT performed at six weeks post-discharge showed markedly reduced abscess size.
Discussion:
K. pneumoniae is a well-known opportunistic nosocomial pathogen. Most community acquired K. pneumoniae can cause pneumonia or urinary infections; however, K. pneumoniae serotype K1 is a major cause of community acquired liver abscess, particularly in East Asia. The K1 strain appears to be highly invasive, affecting relatively healthy hosts like our patient, and causing metastatic complications such as endophthalmitis, necrotizing fasciitis, meningitis, and visceral abscesses. Multi-locus sequence typing on our patient’s isolate shows that it was sequence type 23, a genotype associated with the K1 serotype. An infection with this serotype has a slight male predominance, and patients can present with fever, chills, right upper quadrant pain, leukocytosis, low albumin, and an elevated alkaline phosphatase. Right sided and solitary hepatic lesions are also typical. It is unclear how our patient acquired this strain as he lacked the typical epidemiologic association with East Asia travel or descent. Our case adds to the already growing evidence that community acquired liver abscess with K. pneumoniae K1 strain is expanding beyond Asia as a global disease.
Conclusions:
Our case highlights the growing worldwide incidence of pyogenic liver abscess due to the hypervirulent K. pneumoniae K1 strain. The diagnosis of K. pneumoniae should be considered in all cases of liver abscess, and clinicians should be prompted to closely evaluate these patients for metastatic complications.